Dependence of radio wave reflection and transmission characteristics of reinforced concrete slabs on frequency and angle of incidence

Abstract

AbstractFor effective use of mobile communication systems within a building, it is crucial to know the electromagnetic properties of the materials composing the floors, ceilings, walls, and so on. This paper considers RC (reinforced concrete) slabs, a major component of large buildings, and attempts to develop techniques for predicting and for measuring radio wave reflection and transmission characteristics in various environments. The frequency range considered in the analysis is approximately from 0.3 to 3.5 GHz, which is often used in mobile communications. As the first step, a slab with single‐plane iron bar mesh buried in the concrete is assumed as the basic model for the analysis. A simulation experiment is performed with a 1/10 scale model, using microwaves or millimeter waves. A simulation calculation is also performed with a multiply stratified model, in which the iron mesh plane is replaced by an equivalent dielectric layer. The reflection and transmission characteristics are investigated as functions of the frequency and angle of incidence of the radio waves. The calculation results and measurements agree well, and the effectiveness of the method is verified. The characteristics of the basic analytical model are elucidated. A real floor consisting of metal mesh embedded in concrete is examined. The reflection characteristics for 2.0‐GHz incident waves are examined by simulation calculation and by measurement with a network analyzer. The measurement technique is established and the dependence of the reflection characteristics on the incident polarization and angle of incidence is elucidated. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(1): 69–81, 2002